The present invention relates to wet cleaning systems and, in particular, a wet, or water-based, cleaning system for articles of clothing that have been conventionally dry cleaned. In addition to providing a system for wet cleaning of clothing, the present invention relates to a novel shrinkage prevention agent for use in such a wet cleaning system. The antishrink or shrinkage prevention agent minimizes or prevents the shrinkage of fabric, cloth, clothing, and articles made of hair, silk, rayon, animal hair, animal skin, mixed spun material, and other similar materials that are likely to shrink when washed in water. The system of the present invention includes a method for washing in water of items that would be conventionally dry cleaned, using the novel shrinkage prevention agent.
In general, cleaning in the clothing cleaning industry can be divided into dry cleaning and wet cleaning, which is washing in water. In order to avoid shrinkage caused by washing in water, many clothing items are conventionally dry cleaned. These types of clothing include fabric and other clothing made of hair, silk, rayon, animal hair, animal skin, and mixed spun materials, all of which have a tendency to shrink when they are washed in water. Therefore, at the present time, these items are conventionally only cleaned by dry cleaning. Dry cleaning employs solvents for cleaning, such as chloroethylene, 1,1,1-trichloroethane, 1,1,2-trichloro-1,2,2-trifluoroethane, and perchloroethylene, which is commonly known as "perc." Each of these solvents contain chlorine and they present environmental problems of ozone layer destruction, ground-water pollution, as well as the presence of carcinogenic substances. Accordingly, environmental regulations are restricting the use of freon-system or halogenated solvents, such as the above solvents.
Several prior art systems have been proposed for wet cleaning of clothing that is conventionally dry cleaned. U.S. Pat. No. 5,634,947 to Kazama discloses a wet cleaning system that uses a solvent of propylene glycol monomethyl ether containing 4% to 50% by volume of water. The Kazama patent does not teach or disclose the use of the natural plants and chemical substitutes used in the shrinkage prevention agent of the present invention.
Japanese Patent Application Laid-open No. 7-268,766 discloses a wet cleaning method for items that should be dry cleaned by using shrinkage prevention agent containing a water repelling silicone emulsion, such as water-repellant dimethylpolysiloxane oil, or amine-modified silicone oil, in combination with a detergent.
Japanese Patent Application Laid Open No. 6-340,897 discloses a degreasing agent that contains a water or hot water extract of tea as its active component. The extract is obtained by extracting a nonfermented tea such as green tea, a semifermented tea such as oolong tea, or a fermented tea such as black tea. The degreasing agent is formed by a mixture of one or more of such extracts and then is subjected to ultrasonic vibration.
As noted above, conventional dry-cleaning solvents, such as perc, present environmental pollution problems. Similarly, the silicone emulsion that is disclosed in the Japanese Pat. Application Laid-Open No. 7-268,766 is a nonflammable synthetic chemical substance that presents a ground-water pollution problem, to a degree. Flammable petroleum solvents used instead of the above silicone emulsion can ignite or explode, which also presents safety problems. In addition, dry cleaning with various solvents used to prevent shrinkage do not provide suitable cleaning of water-soluble salt-containing contaminants, such as perspiration, although those solvents can be effective for removal of oil-based stains.
On the other hand, the degreasing detergent of Japanese Patent Application Laid-Open No. 6-340,897 is comprised of extracts of tea so it does not present environmental pollution problems. However, the tannin contained in the tea extract can discolor clothes when it is used for washing clothing. Therefore, although the degreasing agent is suitable for cleaning or degreasing of specific precision machines, it is not suitable for washing clothes.